The only other known case of rabies in a sea mammal was in a ringed seal in Norway's Svalbard islands in the early 1980s. That seal had likely been infected by a rabid arctic fox, researchers said, and there was no evidence of rabies spreading among seals there.

Officials in South Africa say they are experiencing a rabies outbreak among its wild seal population. It's the first time they say an outbreak of the virus has been found in sea mammals. A representative for the city of Cape Town says it received reports of aggressive seals from local residents,